Field of the Invention
The present invention relates to electrostatic generator/motor systems, and more specifically, it relates to means for starting the rotor of such systems from rest and directing the rotation of the rotor in a desired direction.
Description of Related Art
Electrostatic generator/motors of the type described, for example, in U.S. Pat. No. 7,834,513, require means to start them up from zero speed. See also U.S. Pat. No. 9,270,203, incorporated herein by reference. When used in flywheel energy storage systems, there are situations where it is important to be able also to predetermine the direction of rotation, i.e., clockwise or counter-clockwise. An example where this latter requirement arises is when electromagnetic batteries (EMBs) are used in vehicles. In these cases, it may he important to suppress the gyroscopic forces from the flywheel rotors. This requirement can be satisfied by pairing every clockwise-rotating rotor with a counterclockwise one running at the same speed. It is therefore desirable to provide a startup system that is capable of satisfying this rotation direction requirement, in addition to providing a simple means for startup from zero speed.
In the Lawrence Livermore National Laboratory (LLNL) electrostatic generator/motor systems, the motor action function depends on a physics-based relationship between capacity value and the electrostatic forces on the elements that form the capacitor. Specifically, in a condenser made up of a periodic array of stator and rotor electrodes the capacity of which varies as a function of azimuthal position, when a potential is applied to the capacitor, the rotor will experience a force that pulls it M the direction in which the capacity value increases. This force goes to zero at the point of maximum capacity and then reverses in direction if the rotation continues. This means that in the E-S generator/motors, the motoring function occurs only over those azimuthal positions where the capacity increases, and the generator action occurs over those azimuthal regions where the capacity is decreasing. Thus in starting the generator/motor from rest, it is necessary to initially orient the capacitor so that its capacitance is increasing in the direction that one wishes it to rotate, i.e., either clockwise or counter-clockwise. The present invention provides a means for so orienting the capacitor.